Omodaka Kazuko, Takahashi Seri, Matsumoto Akiko, Maekawa Shigeto, Kikawa Tsutomu, Himori Noriko, Takahashi Hidetoshi, Maruyama Kazuichi, Kunikata Hiroshi, Akiba Masahiro, Nakazawa Toru
Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Topcon Corporation, Tokyo, Japan.
PLoS One. 2016 Apr 21;11(4):e0153707. doi: 10.1371/journal.pone.0153707. eCollection 2016.
To investigate the influence of various risk factors on thinning of the lamina cribrosa (LC), as measured with swept-source optical coherence tomography (SS-OCT; Topcon).
This retrospective study comprised 150 eyes of 150 patients: 22 normal subjects, 28 preperimetric glaucoma (PPG) patients, and 100 open-angle glaucoma patients. Average LC thickness was determined in a 3 x 3 mm cube scan of the optic disc, over which a 4 x 4 grid of 16 points was superimposed (interpoint distance: 175 μm), centered on the circular Bruch's membrane opening. The borders of the LC were defined as the visible limits of the LC pores. The correlation of LC thickness with Humphrey field analyzer-measured mean deviation (MD; SITA standard 24-2), circumpapillary retinal nerve fiber layer thickness (cpRNFLT), the vertical cup-to-disc (C/D) ratio, and tissue mean blur rate (MBR) was determined with Spearman's rank correlation coefficient. The relationship of LC thickness with age, axial length, intraocular pressure (IOP), MD, the vertical C/D ratio, central corneal thickness (CCT), and tissue MBR was determined with multiple regression analysis. Average LC thickness and the correlation between LC thickness and MD were compared in patients with the glaucomatous enlargement (GE) optic disc type and those with non-GE disc types, as classified with Nicolela's method.
We found that average LC thickness in the 16 grid points was significantly associated with overall LC thickness (r = 0.77, P < 0.001). The measurement time for this area was 12.4 ± 2.4 minutes. Average LC thickness in this area had a correlation coefficient of 0.57 with cpRNFLT (P < 0.001) and 0.46 (P < 0.001) with MD. Average LC thickness differed significantly between the groups (normal: 268 ± 23 μm, PPG: 248 ± 13 μm, OAG: 233 ± 20 μm). Multiple regression analysis showed that MD (β = 0.29, P = 0.013), vertical C/D ratio (β = -0.25, P = 0.020) and tissue MBR (β = 0.20, P = 0.034) were independent variables significantly affecting LC thickness, but age, axial length, IOP, and CCT were not. LC thickness was significantly lower in the GE patients (233.9 ± 17.3 μm) than the non-GE patients (243.6 ± 19.5 μm, P = 0.040). The correlation coefficient between MD and LC thickness was 0.58 (P < 0.001) in the GE patients and 0.39 (P = 0.013) in the non-GE patients.
Cupping formation and tissue blood flow were independently correlated to LC thinning. Glaucoma patients with the GE disc type, who predominantly have large cupping, had lower LC thickness even with similar glaucoma severity.
利用扫频光学相干断层扫描（SS-OCT；拓普康）研究各种风险因素对筛板（LC）变薄的影响。
这项回顾性研究纳入了150例患者的150只眼睛：22名正常受试者、28名视野检查前青光眼（PPG）患者和100名开角型青光眼患者。在以圆形布鲁赫膜开口为中心的视盘3×3 mm立方体扫描中确定平均LC厚度，在此扫描上叠加一个由16个点组成的4×4网格（点间距：175μm）。LC的边界定义为LC孔隙的可见界限。用Spearman等级相关系数确定LC厚度与Humphrey视野分析仪测量的平均偏差（MD；SITA标准24-2）、视乳头周围视网膜神经纤维层厚度（cpRNFLT）、垂直杯盘比（C/D）以及组织平均模糊率（MBR）之间的相关性。用多元回归分析确定LC厚度与年龄、眼轴长度、眼压（IOP）、MD、垂直C/D比、中央角膜厚度（CCT）和组织MBR之间的关系。按照Nicolela方法分类，比较青光眼性视盘扩大（GE）型患者和非GE型视盘患者的平均LC厚度以及LC厚度与MD之间的相关性。
我们发现16个网格点处的平均LC厚度与整体LC厚度显著相关（r = 0.77，P < 0.001）。该区域的测量时间为12.4±2.4分钟。该区域的平均LC厚度与cpRNFLT的相关系数为0.57（P < 0.001），与MD的相关系数为0.46（P < 0.001）。各组之间的平均LC厚度存在显著差异（正常：268±23μm，PPG：248±13μm，开角型青光眼：233±20μm）。多元回归分析显示，MD（β = 0.29，P = 0.013）、垂直C/D比（β = -0.25，P = 0.020）和组织MBR（β = 0.20，P = 0.034）是显著影响LC厚度的独立变量，但年龄、眼轴长度、IOP和CCT不是。GE患者的LC厚度（233.9±17.3μm）显著低于非GE患者（243.6±19.5μm，P = 0.040）。GE患者中MD与LC厚度的相关系数为0.58（P < 0.001），非GE患者中为0.39（P = 0.013）。
视杯形成和组织血流与LC变薄独立相关。主要有大视杯的GE型视盘青光眼患者，即使青光眼严重程度相似，其LC厚度也较低。
